Experimental verification of multiinput seismic control strategies for smart dampers

This paper documents the results of an experimental study conducted to demo nstrate the capabilities of multiple magnetorheological (MR) devices for se ismic control of civil engineering structures. A six-story test structure i n the Washington University Structural Control and Earthquake Engineering L ab is considered, and four parallel-plate, shear-mode MR dampers are used t o control this test structure. Two control devices are installed in the tes t structure between the base and first floor, and two are installed between the first floor and second floor. A phenomenological model of the shear mo de MR damper is proposed and verified. A nonlinear system identification me thod, appropriate for multi-input/multi-output systems, is used to develop a model of the integrated structural system. Experimental transfer function data corresponding to one system input are used to update the eigenvalues of an analytical model. Two semiactive control algorithms, including a Lyap unov algorithm and a clipped-optimal algorithm, are considered. An El Centr o earthquake example is used to disturb the system at three amplitude level s. The results indicate that high performance levels can be achieved, and t he responses of the semiactive system are significantly better than that of comparable passive systems.